Plug receiving receptacle and contact inserts therefor



Jan. 25, 1966 K. M. HAMMELL 3,231,349

PLUG RECEIVING REGEPTACLE AND CONTACT INSERTS THEREFOR Original Filed Sept. 30 1965 2 Sheets-Sheet 1 Jan. 25, 1966 K. M. HAMMELL 3,231,849

PLUG RECEIVING RECEPTACLE AND CONTACT INSERTS THEREFOR Original Filed Sept. 30, 1963 2 Sheets-Sheet 2 i i in part apparent'and in part pointed outas the United States Patent M Application Sept. 30, 1963, Ser. No. 313,414, which is t! continuation of application Ser. No. 614,551, Oct. 8, 1956. Divided and this application Feb. 8, 1965, Ser. No. 440,977 i i 6 Claims. (Cl. 339-491) This application is a divisionof my co-pending application Serial No. 313,414, filed September 30, 1963, which is, in turn, a continuation of my application Serial No. 614,551, tiled October 8, 1956, now abandoned.

This invention relates to disconnect electrical terminations of the so-called friction type and more particularly to a pin receptacle connector and a pin receptacle cluster block.

V In many applications it is desirable'to terminate wire leads from an apparatus in a group of pins or posts which are adapted to be frictionally engaged in a female receptacle connected to suitable cables for connection to the rest of the electrical circuit. Typical applications for connections of this type are in the refrigerating and air conditioning fields where portions of the equipment are hermetically sealed and connection must be made to a series of pins or posts extending through the shell of the hermetically sealed portion.

Heretofore various pin receptacle connectors have been suggested and have been partially successful for certain limited application. However under severe operating conditions, both temperature and humidity, it has been found that all connections heretofore known have failed to give the desired low resistance contact over a long period of time necessitating either frequent cleaning or replacing of the connections. According to thepresent invention I have discovered that by placing special fwrap-around pin contacting surfaces on a pair of parallel bridge-like flexible spans that a greatly increased contact area of low unit contact pressure can be obtained resulting in a superior long life connection.

It is an object of the present invention to providaa pin receptacle having substantially more than a line or point contact with the pin inserted therein. It is another object of the present invention toprovide a pin receptacle that has low unit contact pressure over a large area of contact. It is another object of the present invention to provide a low contact resistance pin receptacle that will maintain its low resistance contact. throughout a long period of time under adverse atmospheric and tempera ture conditions. It is another object of the present invention to provide a pin receptacle of improved low contact resistance that may be made of cheaper, more readily available materials than heretofore known. It-isanother object of the present invention to provide an improved pin receptacle block that will more securely position the pin receptacle for engagement with the pins to be contacted. It is another object of the present invention to provide a pin receptacle block for connecting a plurality of pin receptacles 'to a plurality of pins that orientsth'e pin receptacle in a :more positive and superior fashion and yet allows proper alignment for greater area contact on each pin as the pin receptacle is connected thereto; It is a still further object of the present invention to provide a pin receptacle with wrap-around contact surfaces to provide substantial areas of contact with a pin inserted therein. These and otherfurther objects will be specification proceeds. G

3,231,849 Patented Jan. 25, 1966 ICC In the drawings:

FIGURE 1 is a side elevation of the pin receptacle of the present invention;

FIGURE 2 is a top plan view of the pin receptacle of the present invention;

FIGURE 3 is an end view of the pin receptacle of FIGURE 2; I

FIGURE 4 is a framentary view of the contact portion of the pin receptacle of FIGURES 1 through 3 prior to insertion of a pin showing the relative curvature of .the pin and contact surfaces thereof;

FIGURE 5 is a view similar to FIGURE 4 showing the pin inserted in the pin receptacle;

FIGURE 6 is a top plan view of the pin receptacle block according to the present invention,.the top surfaces of the cavity walls being cross-hatched for clarity;

FIGURE 7 is -a sectional view on line VII-VII of FIGURE 6;

FIGURE 8 is an end elevation of the block of FIG- URE 6;

FIGURE 9 is a top plan view of the cover of the block of FIGURE 6;

FIGURE 10 is a cross-section on the line XX of 7 FIGURE 9.

FIGURE 11 is a plan view similar to FIGURE 6 showing the pin receptacle inserted in the block;

3 FIGURE 12 is a sectional view taken on line XH; XII of FIGURE 11;

FIGURE 13 is a view similar to FIGURE 6 of another embodiment according to the present invention; 7

FIGURE 14 is a sectional view on line XlV-XIV of F GU E 13;a11d

FIGURE 15 is a cross-sectional view of the cover for the receptacle of FIGURE 13 before insertion of the staple of FIGURE 14. H

Referring now to FIGURE 1 the pin receptacle 26 comprises generally the receptacle portion 22, a barrel portion l tand an insulation support portion 26. The

barrel portion 24 and insulation support portion 26 are of conventional design and crimped according to a well? known crimp and are not described in detail herein for the sake of brevity. The receptacle portion 2'2 comprises generally two-thin gauge spans 28 and 30 which are supported at the top by the tabs 32 and 34 and at the bottom by the U-shaped root sections 36 and respectively of the connector. Each of the spans 28 and 30 at the end of the ears 32 and'34 alocking tab 44 which extends upwardly to engage the side of the opposite spam. 'The locking ears .32 and 34 as they are 'bent around to engage the opposite span seat in a cut-out which cooperates with the tabs 44 to provide the desired support of the upper edges of spans 28 and '30. In-addition to giving the superior performance as will be described herein in actual operation the foregoing con struction together with the root sections '36 and 38 allow an independent control of the width of both the top and bottom of the recepac'le portion 22. in the manufacture thereof which resultsin increased flexibility of the product and better quality control in the manufacturing thereof. e

The spans 28 and 30 are formed of a relatively thin gauge stock so that they are somewhat flexible and act like bridge spans. joined at the end but free to flex in the middle. The contact areas 40 have a radius somewhat greater than the radius of the pin to which they are to be connected and are spaced apart somewhat less than the diameter of the pin to which the receptacle is to be joined. This may be seen in FIGURES 4 and 5. Also the upper edge of the contact surfaces 40 are swaged or otherwise beveled outwardly at 41 in somewhat the manner of a bell mouth to facilitate the entrance of the pin therein.

FIGURE 4 shows receptacle 20 in its normal position with a pin 48 about to enter into the receptacle portion thereof. As may be clearly seen the pin 48 is slightly larger in diameter than the spacing between the contact surfaces 40 of the receptacle 20. However it will be noticed that the radius of curvature of the contact surfaces themselves are greater than the radius of curvature of pin 48. In FIGURE 5 the pin 48 has been inserted into the receptacle and as may be readily seen this has sprung the spans 28 and somewhat apart and in so doing has caused them to wrap around the pin 48 to provide a relatively large area of contact between the contact areas and the pin 48. This flexing has taken place between the suspension points at the top and bottom of the ends of the spans 28 and 30 as previously described. The flexing or bending actually takes place in the contact surface portions 40 insuring a complete and intimate wraparound contact over a substantially larger area of the pin than heretofore possible.

Without the bending of the surfaces 40 contact is obtained along a line such as 43 in FIGURE 4. With the flexing taking place in surfaces 40 a wide area of contact is obtained as between lines and 47 in FIGURE 5.

Since the spans 28 and 30; are of relatively thin gauge metal the pressure necessary to produce this flexing is relatively slight and the actual contact pressure is of a low unit magnitude although the total pressure holding the receptacle on the pin may be considerably greater than that encountered with other types of receptacles having single line or point contacts but very high unit pressures. This not only facilitates the connection and disconnection of the receptacle and pin but also provides a greatly increased life and a much lower average contact resistance between the receptacle and the pin.

With the high unit pressure line or point contact type of receptacle occasionally the initial contact obtained between the receptacle and pin may be greater than that obtained with the receptacle of the present invention. However it has been conclusively found that such a connection in the presence of high temperature and humidity very soon loses its low initial resistance and in a short period of time will have developed a relatively high contact resistance that progressively gets worse until the joint or connection fails. On the contrary with applicants broad area, low unit contact pressure connection while the initial contact resistance may be slightly greater than with other types of high unit pressure contacts the resistance remains substantially constant and does not increase materially under the influence of high temperature and humidity. For instance with the former type line contact, high unit pressure terminal, a terminal temperature of as high as 380 degrees Fahrenheit is not uncommon in an ambient temperature of approximately 200 degrees Fahrenheit. With applicants broad area, low unit contact pressure terminal the maximum temperature observed has been only 250 degrees Fahrenheit with an average somewhere in the neighborhood of 230 degrees Fahrenheit. Furthermore the voltage loss in the connection has been measured at more than 300 millivolts at 5 amperes load for the former, while with applicants connection the average drop has been 15 millivolts with a maximum of between 25 and millivolts. It is obvious from this data that the minimum service life of a connection according to the present invention would be many times that of a connection of the line or point, high unit contact pressure type.

This low temperature of applicants receptacle has a further advantage in that it is possible to utilize cheaper materials since the temperature requirements are not as severe. For instance, in the example given above it is possible to use with applicants receptable a Phosphor bronze material which has very satisfactory creep stabil-- ity at the 250 degree Fahrenheit maximum temperature encountered, however, with the line contact type of terminal a beryllium copper which is three to four times as expensive is necessary if creep stability is to be maintained at the elevated temperature of 380 degrees Fahrenheit encountered with that type of connection.

Referring again to FIGURES 1 through 5 it will be noted that the spans 28 and 30 are substantially parallel from top to bottom thereof and that in actual application such as FIGURE 5 they are still substantially parallel from top to bottom. This, it has been found, is a very important feature of applicants pin receptacle in that if the contact are-as 40 are not maintained substantially parallel when the pin 48 is inserted therein it will cause a spreading out of the contact areas such that only a line or ring contact is established at the lower or upper end so that only a very small area of contact will be obtained at either the upper or lower end of the contact surfaces 40. As described herein, by adjusting the locking ears 32 and 34 and the spans 36 and 38 during the manufacture of the receptacle the spans 28 and 30 will be maintained very closely parallel. In actual operation I have found that if the distance between the tops of the spans 28 and 30 is not over twoto three-thousandths greater and not over four-thousandths less than the distance at the bottom that uniform low resistance contact throughout the entire length of the contact area 40 will be obtained.

Referring now to FIGURE 1 a cut-out 50 will be seen at the bottom of the receptacle 20. This is provided to ensure the resilient bridge span action of the spans 28 and 30. The slots 42 help in the accurate forming of contact surfaces 40 and under certain conditions help to reduce the frictional drag where ease of application is of paramount consideration.

FIGURES 6 through 10 show the receptacle block 60 which comprises generally a molded triple cavity bottom portion 62 having an open top and three holes 64 drilled in the bottom thereof with three receptacle cavities 66 centered about the holes 64. Each cavity 66 is molded so as to support the pin receptacle therein in an accurate floating fashion to properly align the contact surfaces 46 about the pin 48 as the block 60 is applied to a corresponding group of pins. To accomplish this each cavity has front and back stops 68 and 70 which cooperate with the locking ears 32 and 34 (see FIGURES 11 and 12) to position the receptacle longitudinally within the cavity 66. Also each cavity has therein side stops 72-72 and 74-74 which engage the sides of the pin receptacle and in cooperation with the ends of ears 32 and 34 abutting on the opposite walls (FIGURE 11) align the pin receptacles laterally within the cavities 66. I thus obtain a six-point positioning within the cavities 66 and in the manufacture of the block and receptacle a nominal .01 float is maintained so that the receptacle may be aligned properly on the pin when connected thereto to ensure full wide area contacts throughout the entire length of the surfaces 40.

To hold the pin receptacles 20 within the block 60 there is provided a cover plate 76 which has beveled edges 78 (see FIGURE 10) which cooperate with inwardly beveled edges 80 of the block 60 (see FIGURE 8) to securely hold the cover plate 76 over the receptacles 20 and to properly position them within their respective cavities 66. A small detent 82 is punched into the cover 76 so as to engage the hole 84 in the block 60 when the cover is in the fully closed position. This locks the cover plate 76 in position so that it cannot accidentally fall out. To facilitate the insertion of the cover plate 76 a small taining a secure looking on M 4 In the closed pm ,1 URE 12 it can seen how the cover 76 aceura ly holds the receptacle '20 within the cavities 66 that theyaie roperly and are- 1 curately oriented relative to holes 64 and the pins to be e re nv .6 r t p i The plate 76 is generally at s laminated though other materials ahd cfoiifi'gtir atioiis may be u d. The tapered groove etfeet ofjth surf ea '80 in 1516 k 60 provides a simple yet adejquateehgagenrent foi the "cover plate 76 yet permits a block forn' r that is sunsets-ping 'from the mold so that the block 60 ma be quickly and ecpnomically manufactured. I

If for any reason thereceptacles fare subjected to severe lifting or the insulation is extra thick the cbver 76 may be secured firmly into the block 60 by inserting a small screw (not shown through the detent 82 into the hole 84 to securely "engage thecover to the block 60.

It will be noted that the holes 64 are drilled in the bottom of the molded block 60 which rovides a much 'stronger and more rigid opening through the block so that when it is pried from the pins the block will not be damaged in any manner. 4. a 3

Referring now to FIGURES 13 through there is shown another embodiment of the receptacle block according to the present invention. In certain applications it is desired that the insulation supporting portion of the block 60 extend in the opposite direction or a differentdirection from that as shown in FIGURES 6 through 10. In such situations a block 60' such as that shown in FIGURE 13 has been found to be advantageous. As may be readily seen the central cavity 66 is in the full left position of FIGURE '13 while the two outer cavities are in the right hand position. The individual cavities 66' are the same as in the embodiment of FIGURE 6 but there is provided a pair of holes 90 in place of the retaining hole 84 of FIGURE 6. It will also be seen that these holes are somewhat rectangular rather than circular and are chamfered for easy entrance at the top. As may be seen in FIGURE 15 the cover plate 76' carries thereon a pair of indentations 92 rather than the single locking notch 82 of FIGURE 10. As maybe seen in FIGURE 14 when it is desiredto more securely fasten the cover plate 76 to the block 60 a corrugated staple 94 is, driven through the indentations 9 2 into the holes 90 to securelyhold the I cover plate 76 thereon.

If it is desired to remove the cover plate 76 or 76' after it has been secured by a staple or screw this may be readily accomplished by inserting a small instrument through the bottom of hole 84 or 90. As may be readily seen in FIGURE 7 the holes 84 and 90 extend very closely to the bottom of the block 60 or 60" as the case may be so that it is very simple to break the cap 96 and drive the staple or screw from the hole. 1

While there is given above certain specific examples of this invention and its application in practical use, it should be understood that this is not intended to be exhaustive or to be limiting of the invention. On the contrary, these illustrations and explanations herein are given in order to acquaint others skilled in the art with this invention and the principles thereof and a suitable manner of its application in practical use, so that others skilled in the art may be enabled to modify the invention and to adapt and apply it in numerous forms each as may be best suited to the requirement of a particular use.

I claim:

1. An electrical connector cluster block adapted to receive therein three electrical connectors each having a receptacle contact portion and an electrical conductor g portion compiisihg' in combination a molded "shell member or generally rectangular configuration; longitudinal cavities disposed side by side therein, cavities being open on one end and said shell being open on the top to expose said cavities; a receptacle receivjing portion and an electrical conductor supporting portion ineach of said cavities; three spaced holes in the bottom er said shell one each disposed in the receptacle portions or each of said cavities; longitudinal stop members positioned at eaeh end of said receptacle portions of said es to longitudinally orient said receptacle contact portion relative to said holes said shell; side stop disposed adjacent each end of said receptacle contact areas in said cavities to laterally align said cl'e cofitact portions relative to said holes and to main in them in a substantially perpendicular relationship to the bottom of said shell; a cover plate for the open top of said shell having tapered longitudinal edges; a pair or tapered tracks 'along'the longitudinal edges of said open shell sides adapted to receive therein said cover plate; a sever locking receptacle mou'ntedin said shell ue'rweea said cavities "and adapted to receive therein a screw, detent or other locking means; and locking means said 'ciaver adapted to cooperate with said cover locking reeepwcle -2-'. A device as described in clairn 1 wherein said locking receptacle can is'e's aholemolded in said shell between said cavities and said locking means comprises a small fastenermember inserted through the detent area 'of said cover plate into said hole to securely hold said cover plate in the -closed position in said block. -3. An electrical connector cluster block of the type adapted to receive therein a plurality of electrical connectors in a predetermined relationship for connection to cooperating electrical terminals and the like comprising in combination a molded outer shell open on one side and having therein a plurality of longitudinal cavities; a plurality of holes punched in the closed side of said shell, one in each of said cavity areas; a cover plate having, outwardly tapered edges for closing the open side of said shell; a pair of inwardly tapered grooves adjacent each longitudinal edge of the open side of said shell adapted to receive therein tapered edges of said cover plate; locking means for retaining said cover plate in a closed position in said shell; each of said cavities having a contact receiving area and an insulation supporting area; said contact receiving areas having front and rear stop members positioned adjacent to and on opposite sides of said holes; and a pair of side stops, extending from top to bottom of said cavities, positioned adjacent the ends of said contact receiving area and on opposite sides thereof about said hole; said insulation supporting areas of said cavities being generally of more restricted dimensions than said receptacle receiving areas whereby said I electrical connectors are securely and accurately positioned in said cavities in proper alignment about the holes therein to receive said electrical terminals in low resistance contact.

4. A device as described in claim 3 wherein said looking means includes a small hole in said shell and a cooperating detent in said cover plate, the portion adjacent said hole in said shell having a tapered ramp disposed to earn said detent over the edge portions defining said hole for seating the detent, and a small opening in the closed end of said shell providing access to the interior side of said cover plate adjacent said detent for unlatching said detent from said hole.

5. An electrical connector cluster block adapted to receive therein three electrical connectors each having a receptacle contact portion and an electrical conductor engaging portion comprising in combination a molded outer shell member of generally rectangular configuration; three longitudinal cavities disposed side by side in said shell, the two outer cavities extending to the closed end and the middle cavity extending only slightly past the 7 middle of said shell, said cavities being open on one end and said shell being open on the top to expose said cavities; a receptacle receiving portion and an electrical conductor supporting portion in each of said cavities; three spaced holes in the bottom of said shell one each disposed in the receptacle portions of each of said cavities; longitudinal stop members positioned at each end of said receptacle portions of said cavities to longitudinally orient said receptacle contact portion relative to said holes in said shell; side stop members disposed adjacent each end of said receptacle contact areas in said cavities to laterally align said receptacle contact portions relative to said holes and to maintain them in a substantially perpendicular relationship to the bottom of said shell; a cover plate for the open top of said shell having tapered longitudinal edges; a pair of inwardly portion comprising a molded outer shell member of generally rectangular configuration; plural longitudinal cavities disposed side by side therein, said cavities being open on one end and said shell being open on the top to expose said cavities; a receptacle receiving portion and an electrical conductor supporting portion in each of said cavities; spaced holes-in the bottom of said-shell, one each disposed in the receptacle portions of each of said cavities; longitudinal stop members positioned at each end of said receptacle portion of said cavities to longitudinally orient said receptacle contact portion relative to said holes in said shell; side stop members disposed adjacent each end of said receptacle contact areas in said cavities to laterally align said receptacle contact portions relative to said holes and to maintain them in a substantially perpendicular relationship to the bottom of said shell; a cover plate for the open top of said shell having longitudinal edges; a pair of tracks along the longitudinal edges of said open shell sides adapted to receive therein said cover plate; a

cover plate locking abutment in'said shell; and locking means on said cover plate adapted to cooperate with said cover locking abutment, said abutment interfering with the sliding movement of said cover plate, said cover plate being yieldable outwardly to disengage the locking means relatively laterally away from said abutment for releasing and shifting the cover plate to an open position exposing said cavities for insertion of said electrical contacts.

References Cited by the Examiner UNITED STATES PATENTS 697,436 4/1902 Betts 2204l 1,895,791 1/1933 Garford 2203.8 2,267,080 12/1941 Clay.

2,663,457 12/1953 Shaffer 220-41 2,720,636 10/1955 McKinley 339192 2,728,060 12/1955 Doeg 339-192 JOSEPH D. SEERS, Primary Examiner. 

1. AN ELECTRICAL CONNECTOR CLUSTER BLOCK ADAPTED TO RECEIVE THEREIN THREE ELECTRICAL CONNECTORS EACH HAVING A RECEPTACLE CONTACT PORTION AND AN ELECTRICAL CONDUCTOR ENGAGING PORTION COMPRISING IN COMBINATION A MOLDED OUTER SHELL MEMBER OF GENERALLY RECTANGULAR CONFIGURATION; THREE LONGITUDINAL CAVITIES DISPOSED SIDE BY SIDE THEREIN, SAID CAVITIES BEING OPEN ON ONE END AND SAID SHELL BEING OPEN ON THE TOP TO EXPOSE SAID CAVITIES; A RECEPTACLE RECEIVING PORTION AND AN ELECTRICAL CONDUCTOR SUPPORTING PORTION IN EACH OF SAID CAVITIES; THREE SPACED HOLES IN THE BOTTOM OF SAID SHELL ONE EACH DISPOSED IN THE RECEPTACLE PORTIONS OF EACH OF SAID CAVITIES; LONGITUDINAL STOP MEMBERS POSITIONED AT EACH END OF SAID RECEPTACLE PORTIONS OF SAID CAVITIES OF LONGITUDINALLY ORIENT SAID RECEPTACLE CONTACT PORTION RELATIVE TO SAID HOLES IN SAID SHELL; SIDE STOP MEMBERS DISPOSED ADJACENT EACH END OF SAID RECEPTACLE CONTACT AREAS IN SAID CAVITIES TO LATERALLY ALIGN SAID RECEPTACLE CONTACT PORTIONS RELATIVE TO SAID HOLES AND TO MAINTAIN THEM IN A SUBSTANTIALLY PERPENDICULAR RELATIONSHIP TO THE BOTTOM OF SAID SHELL; A COVER PLATE FOR THE OPEN TOP OF SAID SHELL HAVING TAPERED LONGITUDINAL EDGES; A PAIR OF TAPERED TRACKS ALONG THE LONGITUDINAL EDGES OF SAID OPEN SHELL SIDES ADAPTED TO RECEIVE THEREIN SAID COVER PLATE; A COVER LOCKING RECEPTACLE MOUNTED IN SAID SHELL BETWEEN SAID CAVITIES AND ADAPTED TO RECEIVE THEREIN A SCREW, DETENT OR OTHER LOCKING MEANS; AND LOCKING MEANS IN SAID COVER ADAPTED TO COOPERATE WITH SAID COVER LOCKING RECEPTACLE. 